The new coronavirus can infect the cells responsible for oxygen exchange in the lungs. It can also spread from the lungs to other organs, and the rate of replication is much faster than SARS. (HKU)

The secrets of a new and very deadly strain of SARS are revealed in recent studies by two groups of researchers, who explain where and how in the human body the new virus attacks its victims; they also explore a possible anti-viral treatment, and explain how animals can carry the infection to humans.

The University of Hong Kong research reveals that the virulent new SARs coronavirus (HCoV-EMC) infects and spreads in human lung tissue much faster than the original SARS, causing swift, severe lung injury and often death. A second study published in Nature by a group in the Netherlands, pinpointed the location that the virus targets to infect its victims.

The team of researchers at the Centre of Influenza Research of the School of Public Health at University of Hong Kong have discovered the mechanism the new virus uses to infect and spread so quickly, even to other organs. They recently published their research in the Journal of Virology, an international publication.

The HKU study found the new SARS coronavirus infects two types of tissue deep in the human lung. The virus attacks the lung cells responsible for infusing oxygen into the blood while removing carbon dioxide (the alveolar epithelial cells) and also attacks the cells that repair damaged lung tissue. This double-barreled attack will result in impaired breathing while hindering the victims’ recovery from the infection.

The study also found that the new SARS can infect the cells lining the veins in the lungs (pulmonary vascular endothelial cells) and thus can be spread through the blood to organs outside the respiratory tract.

The researchers found that, fortunately, Interferon therapy can be effective in inhibiting the replication of the virus, offering some hope in combating the infections.

The second group of findings, published by a European team at the Erasmus Medical Centre in Rotterdam, the Netherlands, found that the virus latches on to a well-known receptor protein on some lung cells and thus gains entry into the system. Because the receptor is not present on all the cells, and the cells are deep within the lungs, it is suggested by the team that the infection, though severe, would not be easy to contract.

This team also conjectured that because the receptor is present in many mammals, the coronavirus infection could be present in other animals, and might possibly jump the species barrier as other viruses do. The virus has already been found in bats, and researchers are looking into whether it could find other hosts.

Because of its deadly potential, this new strain of SARS coronavirus, which is related to the SARS that originated in southern China in 2003, is of particular interest to researchers. The original SARS infected at least 8,000 people and killed at least 775 people worldwide.